AERMOD Updates

AERMOD UpdatesAERMOD Updates

Robert Opiela, Technical Robert Opiela, Technical SpecialistSpecialist

Technical Program Support Technical Program Support SectionSection

TCEQ, Air Permits DivisionTCEQ, Air Permits Division

Austin, TexasAustin, Texas

April 30, 2008April 30, 2008

IntroductionIntroduction

• Model UpdatesModel Updates

• Modeling Guidance UpdatesModeling Guidance Updates

Model UpdatesModel Updates

• AERMET/AERMAPAERMET/AERMAP– 0634106341– Mainly bug fixesMainly bug fixes

• AERMODAERMOD– 0702607026– Mainly bug fixesMainly bug fixes– Only works with AERMET 06341 dataOnly works with AERMET 06341 data

Model Guidance UpdatesModel Guidance Updates

• Meteorological Data InputsMeteorological Data Inputs– What to doWhat to do– How to do itHow to do it– How to document itHow to document it– Does it make any sense?Does it make any sense?

Examples of Low RoughnessExamples of Low Roughness

Examples of Medium Examples of Medium RoughnessRoughness

Examples of High Examples of High RoughnessRoughness

Appropriate RoughnessAppropriate Roughness

• Define Appropriate Modeling DomainDefine Appropriate Modeling Domain– Depends upon sources in projectDepends upon sources in project

•Low-level dominated, domain is smallLow-level dominated, domain is small

•High, hot stacks, domain is largeHigh, hot stacks, domain is large

– Area that influences the source mostArea that influences the source most

Appropriate RoughnessAppropriate Roughness

• Qualitative AnalysisQualitative Analysis– Land use is clearly dominant in Land use is clearly dominant in

modeling domainmodeling domain– Minimal explanation necessaryMinimal explanation necessary

Qualitative ExampleQualitative Example

Appropriate RoughnessAppropriate Roughness

• Quantitative AnalysisQuantitative Analysis– Data source of values usedData source of values used– Define land use categoriesDefine land use categories– Show ALL calculationsShow ALL calculations– Document ALL selectionsDocument ALL selections

Quantitative ExampleQuantitative Example

Use of Urban OptionUse of Urban Option

• Questionable ApplicationQuestionable Application– Light windsLight winds– Clear skiesClear skies– May not be applicable in sub-tropical May not be applicable in sub-tropical

conditionsconditions

Use of Urban OptionUse of Urban Option

• Questionable ApplicationQuestionable Application– Uncertain of model implementationUncertain of model implementation– Unclear on use of population dataUnclear on use of population data

• Selection is AllowedSelection is Allowed– Provide a strong justification for Provide a strong justification for

selectionselection

Use of Terrain DataUse of Terrain Data

• Document Data SourceDocument Data Source

• Do Not Interpolate DataDo Not Interpolate Data– Use value of gridUse value of grid– May supplement if grid resolution not May supplement if grid resolution not

sufficientsufficient

Streamlining Review Streamlining Review ProcessProcess

• Use Modeling Input Data TemplatesUse Modeling Input Data Templates

• Consult with ADMT Staff Early in ProcessConsult with ADMT Staff Early in Process

• Document Document ALLALL Selections, Assumptions, Selections, Assumptions, etc.etc.

• Not Following Guidance Causes DelaysNot Following Guidance Causes Delays

SummarySummary

• Use Latest Versions of AERMOD Use Latest Versions of AERMOD SystemSystem

• Follow Guidance on Model SelectionsFollow Guidance on Model Selections

• Assist in Streamlining Review ProcessAssist in Streamlining Review Process

• Be a Part of the SolutionBe a Part of the Solution

QuestionsQuestions